java Date常用日期功能综合

package com.yao.util.date;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
public class DateUtil {
public static String defaultSimpleFormater = "yyyy-MM-dd hh:mm:ss";
/**
* 默认简单日期字符串
*
* @return
*/
public static String getDefaultSimpleFormater() {
   return defaultSimpleFormater;
}
/**
* 设置默认简单日期格式字符串
*
* @param defaultFormatString
*/
public static void setDefaultSimpleFormater(String defaultFormatString) {
   DateUtil.defaultSimpleFormater = defaultFormatString;
}
/**
* 格式化日期
*
* @param date
* @param formatString
* @return
*/
public static String format(Date date, String formatString) {
   SimpleDateFormat df = new SimpleDateFormat(formatString);
   return df.format(date);
}
/**
* 格式化日期(使用默认格式)
*
* @param date
* @return
*/
public static String format(Date date) {
   return format(date, defaultSimpleFormater);
}
/**
* 转换成日期
*
* @param dateString
* @param formatString
* @return
*/
public static Date parse(String dateString, String formatString) {
   SimpleDateFormat df = new SimpleDateFormat(formatString);
   try {
    return df.parse(dateString);
   } catch (ParseException e) {
    return null;
   }
}
/**
* 转换成日期(使用默认格式)
*
* @param dateString
* @return
*/
public static Date parse(String dateString) {
   return parse(dateString, defaultSimpleFormater);
}
/**
* 昨天
*
* @return
*/
public static Date yesterday() {
   return addDay(-1);
}
/**
* 明天
*
* @return
*/
public static Date tomorrow() {
   return addDay(1);
}
/**
* 现在
*
* @return
*/
public static Date now() {
   return new Date(System.currentTimeMillis());
}
/**
* 按日加
*
* @param value
* @return
*/
public static Date addDay(int value) {
   Calendar now = Calendar.getInstance();
   now.add(Calendar.DAY_OF_YEAR, value);
   return now.getTime();
}
/**
* 按日加,指定日期
*
* @param date
* @param value
* @return
*/
public static Date addDay(Date date, int value) {
   Calendar now = Calendar.getInstance();
   now.setTime(date);
   now.add(Calendar.DAY_OF_YEAR, value);
   return now.getTime();
}
/**
* 按月加
*
* @param value
* @return
*/
public static Date addMonth(int value) {
   Calendar now = Calendar.getInstance();
   now.add(Calendar.MONTH, value);
   return now.getTime();
}
/**
* 按月加,指定日期
*
* @param date
* @param value
* @return
*/
public static Date addMonth(Date date, int value) {
   Calendar now = Calendar.getInstance();
   now.setTime(date);
   now.add(Calendar.MONTH, value);
   return now.getTime();
}
/**
* 按年加
*
* @param value
* @return
*/
public static Date addYear(int value) {
   Calendar now = Calendar.getInstance();
   now.add(Calendar.YEAR, value);
   return now.getTime();
}
/**
* 按年加,指定日期
*
* @param date
* @param value
* @return
*/
public static Date addYear(Date date, int value) {
   Calendar now = Calendar.getInstance();
   now.setTime(date);
   now.add(Calendar.YEAR, value);
   return now.getTime();
}
/**
* 按小时加
*
* @param value
* @return
*/
public static Date addHour(int value) {
   Calendar now = Calendar.getInstance();
   now.add(Calendar.HOUR_OF_DAY, value);
   return now.getTime();
}
/**
* 按小时加,指定日期
*
* @param date
* @param value
* @return
*/
public static Date addHour(Date date, int value) {
   Calendar now = Calendar.getInstance();
   now.setTime(date);
   now.add(Calendar.HOUR_OF_DAY, value);
   return now.getTime();
}
/**
* 按分钟加
*
* @param value
* @return
*/
public static Date addMinute(int value) {
   Calendar now = Calendar.getInstance();
   now.add(Calendar.MINUTE, value);
   return now.getTime();
}
/**
* 按分钟加,指定日期
*
* @param date
* @param value
* @return
*/
public static Date addMinute(Date date, int value) {
   Calendar now = Calendar.getInstance();
   now.setTime(date);
   now.add(Calendar.MINUTE, value);
   return now.getTime();
}
/**
* 年份
*
* @return
*/
public static int year() {
   Calendar now = Calendar.getInstance();
   return now.get(Calendar.YEAR);
}
/**
* 月份
*
* @return
*/
public static int month() {
   Calendar now = Calendar.getInstance();
   return now.get(Calendar.MONTH);
}
/**
* 日(号)
*
* @return
*/
public static int day() {
   Calendar now = Calendar.getInstance();
   return now.get(Calendar.DAY_OF_MONTH);
}
/**
* 小时(点)
*
* @return
*/
public static int hour() {
   Calendar now = Calendar.getInstance();
   return now.get(Calendar.HOUR);
}
/**
* 分钟
*
* @return
*/
public static int minute() {
   Calendar now = Calendar.getInstance();
   return now.get(Calendar.MINUTE);
}
/**
* 秒
*
* @return
*/
public static int second() {
   Calendar now = Calendar.getInstance();
   return now.get(Calendar.SECOND);
}
/**
* 星期几(礼拜几)
*
* @return
*/
public static int weekday() {
   Calendar now = Calendar.getInstance();
   return now.get(Calendar.DAY_OF_WEEK) - 1;
}
/**
* 是上午吗?
*
* @return
*/
public static boolean isAm() {
   Calendar now = Calendar.getInstance();
   return now.get(Calendar.AM_PM) == 0;
}
/**
* 是下午吗?
*
* @return
*/
public static boolean isPm() {
   Calendar now = Calendar.getInstance();
   return now.get(Calendar.AM_PM) == 1;
}
}